In general, a non-aqueous electrolyte secondary battery is manufactured in such a way that after a positive electrode and a negative electrode are wound or laminated with at least one separator interposed therebetween to form an electrode body, this electrode body is received in an outer package together with a non-aqueous electrolyte.
As a non-aqueous solvent used for the non-aqueous electrolyte, in order to secure the safety of the battery and to suppress the degradation of performance of the battery, a non-aqueous solvent containing a fluoroethylene carbonate and a chain ester, such as dimethyl carbonate, has been known (for example, see Patent Literature 1). In addition, according to Patent Literature 1, it is believed that by a flame-retardant function of the fluoroethylene carbonate, the safety of the battery is secured, and by the chain ester, an increase in viscosity of the non-aqueous electrolyte is suppressed, so that the degradation of performance of the battery is suppressed.
Incidentally, in general, the non-aqueous electrolyte secondary battery is provided with a current interrupt device (CID) which interrupts a charge current when the pressure inside the outer package is increased to a predetermined value or more. For example, when the battery is placed in an overcharged state, although a solvent and the like of the non-aqueous electrolyte is electrolyzed to generate gases, this current interrupt device interrupts a charge path of the battery in response to this gas generation, and as a result, a further overcharge is prevented.
As a method to enable the current interrupt device described above to more rapidly function, a method in which lithium carbonate is added to the positive electrode has been known (for example, see Patent Literature 2). According to Patent Literature 2, since lithium carbonate is added in advance into the positive electrode, lithium carbonate is decomposed during overcharge, and a carbon dioxide gas is generated, so that during overcharge, the current interrupt device is able to rapidly function.